public void Zlib_BasicDictionaryDeflateInflate()
{
int rc;
int comprLen = 40000;
int uncomprLen = comprLen;
byte[] uncompr = new byte[uncomprLen];
byte[] compr = new byte[comprLen];
//long dictId;
ZlibCodec compressor = new ZlibCodec();
rc = compressor.InitializeDeflate(CompressionLevel.BestCompression);
Assert.AreEqual<int>(ZlibConstants.Z_OK, rc, String.Format("at InitializeDeflate() [{0}]", compressor.Message));
string dictionaryWord = "hello ";
byte[] dictionary = System.Text.ASCIIEncoding.ASCII.GetBytes(dictionaryWord);
string TextToCompress = "hello, hello! How are you, Joe? I said hello. ";
byte[] BytesToCompress = System.Text.ASCIIEncoding.ASCII.GetBytes(TextToCompress);
rc = compressor.SetDictionary(dictionary);
Assert.AreEqual<int>(ZlibConstants.Z_OK, rc, String.Format("at SetDeflateDictionary() [{0}]", compressor.Message));
int dictId = compressor.Adler32;
compressor.OutputBuffer = compr;
compressor.NextOut = 0;
compressor.AvailableBytesOut = comprLen;
compressor.InputBuffer = BytesToCompress;
compressor.NextIn = 0;
compressor.AvailableBytesIn = BytesToCompress.Length;
rc = compressor.Deflate(FlushType.Finish);
Assert.AreEqual<int>(ZlibConstants.Z_STREAM_END, rc, String.Format("at Deflate() [{0}]", compressor.Message));
rc = compressor.EndDeflate();
Assert.AreEqual<int>(ZlibConstants.Z_OK, rc, String.Format("at EndDeflate() [{0}]", compressor.Message));
ZlibCodec decompressor = new ZlibCodec();
decompressor.InputBuffer = compr;
decompressor.NextIn = 0;
decompressor.AvailableBytesIn = comprLen;
rc = decompressor.InitializeInflate();
Assert.AreEqual<int>(ZlibConstants.Z_OK, rc, String.Format("at InitializeInflate() [{0}]", decompressor.Message));
decompressor.OutputBuffer = uncompr;
decompressor.NextOut = 0;
decompressor.AvailableBytesOut = uncomprLen;
while (true)
{
rc = decompressor.Inflate(FlushType.None);
if (rc == ZlibConstants.Z_STREAM_END)
{
break;
}
if (rc == ZlibConstants.Z_NEED_DICT)
{
Assert.AreEqual<long>(dictId, decompressor.Adler32, "Unexpected Dictionary");
rc = decompressor.SetDictionary(dictionary);
}
Assert.AreEqual<int>(ZlibConstants.Z_OK, rc, String.Format("at Inflate/SetInflateDictionary() [{0}]", decompressor.Message));
}
rc = decompressor.EndInflate();
Assert.AreEqual<int>(ZlibConstants.Z_OK, rc, String.Format("at EndInflate() [{0}]", decompressor.Message));
int j = 0;
for (; j < uncompr.Length; j++)
if (uncompr[j] == 0)
break;
Assert.AreEqual<int>(TextToCompress.Length, j, String.Format("Unequal lengths"));
int i = 0;
for (i = 0; i < j; i++)
if (TextToCompress[i] != uncompr[i])
break;
Assert.AreEqual<int>(j, i, String.Format("Non-identical content"));
var result = System.Text.ASCIIEncoding.ASCII.GetString(uncompr, 0, j);
TestContext.WriteLine("orig length: {0}", TextToCompress.Length);
TestContext.WriteLine("compressed length: {0}", compressor.TotalBytesOut);
TestContext.WriteLine("uncompressed length: {0}", decompressor.TotalBytesOut);
TestContext.WriteLine("result length: {0}", result.Length);
TestContext.WriteLine("result of inflate:\n{0}", result);
}
